WebMD's app is a good place to start to get the latest data on flu outbreaks not just in your city but in your zip code.
Once you have the free app open, search for cold and flu to get to their cold and flu health center with its handy map and other resources.
The app collects data from other WebMD users around the country to best pinpoint where local outbreaks are happening practically in real time.
Another great tool the Center for Disease Control and Prevention's flu tracker site.
That will bring you to a page with hundreds of resources for learning about flu symptoms and treatments and of course where it's popping up around the US.
The data is updated weekly when physicians report the number of sick patients that come to their offices.
And finally Google has its own flu tracking page at google.org/flutrends.
Find data for flu outbreaks around the world and state by state.
Google gets its data through searches.
They say the more people who search for a flu or related terms creates patterns that correlate with real outbreaks.
In San Francisco I'm Kara Tsuboi CNET.com for